China takes major step in creating a global network for quantum communication

China has just launched a major satellite. Picture: AP/Xinhua, Li Gang.

IN THE early hours of Tuesday morning, from a launch pad in the Gobi Desert, China carried out what could prove to be a defining moment in the country’s global ascendancy.

At 1:40am local time, China successfully launched its first quantum satellite — a mission that will be watched very closely by security agencies around the world.

Not only does the launch put the nation of 1.35 billion at the forefront of a unique scientific field but, more importantly, it puts Beijing far ahead of its global rivals in achieving the holy grail of cyber security: a digital communication system impervious to hackers.

By launching a group of quantum-enabled satellites, China hopes to create a super secure network that uses an encryption technique based on the principles of a field known as quantum communication.

While traditional forms of encryption rely on mathematical functions that are very difficult to be reversed, scientists have demonstrated a far better way to transmit secret data.

“In physics we are trying, and we have demonstrated some encryption techniques that rely on the law of physics rather than the mathematical complexity and we call this quantum key distribution,” Professor Ping Koy Lam from the ANU’s Department of Quantum Science told news.com.au prior to the launch.

“For that to work you need to send laser beams that carry certain information, quantum information, and then you need the senders and the receivers to get together to find a protocol to secure the communication.”

In the case of the 600kg Chinese satellite launched this morning, a crystal at the centre of the spacecraft will produce pairs of entangled photons, which will be used like a laser beam imbued with information.

Once in orbit the satellite will send the partners of the entangled photons to bases on the ground in Beijing and Vienna (Austria is a partner in the launch) to create a secret key used to access the information carried in the transmission.

The reason it can’t be hacked is because the information carried in the quantum state of a particle cannot be measured or cloned without destroying the information itself.

“We can show that this kind of quantum encryption works in a city radius or at most between two nearby cities,” Prof Lam said.

However China believes the atmosphere in space will allow the photons to travel further without disruption because “in space there’s nothing to attenuate light.”

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Quantum technology has been a major focus of China’s five-year economic development plan, released in March.

While other space agencies have been experimenting with the technology, none have seen the level of financial support provided by Beijing.

China has not disclosed how much money it has spent on Quantum research, but funding for basic research which includes quantum physics was $US101 billion in 2015 — an absolutely massive increase from the $US1.9 billion the country spent in 2005.

Scientists in the US, Canada, Europe and Japan are also rushing to exploit the power of particle physics to create truly clandestine communication, but China’s launch puts them far ahead of their global counterparts.

In fact the physicist leading the Chinese project, Pan Jianwei, earned his PhD at the University of Vienna under the tutelage of physicist Anton Zeilinger (also working on the project) who has been trying to convince the European agency to launch a similar satellite since 2001.

There is little doubt in the minds of experts that the China-led launch will intensify the latest space race.

“There’s been a race to produce a quantum satellite, and it is very likely that China is going to win that race,” Nicolas Gisin, a professor and quantum physicist at the University of Geneva told the Wall Street Journal.

“It shows again China’s ability to commit to large and ambitious projects and to realise them.”

However Professor Greg Austin from UNSW’s Australian Centre for Cyber Security warned that it was a mistake to think of it as solely a Chinese project.

“You can’t just say that because it was launched in China, this is a Chinese project. This is definitely an international collaboration,” he pointed out, referring to the Austrian researchers involved.

He said it was an “important scientific development” and that the resulting advances will be available to us, just like China.

“This is not about war and peace, this is about economic development and the security of communication,” he told news.com.au.

Deputy chief engineer Zhou Yilin (third from left) discusses with other technicians beside the quantum satellite at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China.Source:Supplied

The China-led project is easily the most ambitious, but other international efforts are steadily working towards a similar goal.

Universities in the UK and Singapore have teamed up and are using inexpensive 5kg satellites known as cubesats to do quantum experiments in space. Next year they hope to launch a craft which can produce fully entangled pairs of photons.

Canadian researchers are planning on generating entangled photons on the ground and then beaming them to a satellite in space.

The European Space Agency and Japan are also looking to take the technology into the cosmos while NASA is leading a future quantum experiment aboard the International Space Station.

China’s satellite still needs to successfully carry out the tasks it was designed for and with the level of sophistication there is still plenty that could go wrong.

But if all goes according to plan, China will following Tuesday’s launch with plenty more quantum satellites as researchers believe they will need about 20 spacecrafts to complete the global network.